Frequently Asked Questions

SEER is Seasonal Energy Efficiency Rating. It's basically a benchmark that tells
you how efficient a piece of equipment may be. Mostly you would use this rating
when comparing different brands of equipment, to ensure that you're comparing
similar products. A SEER is an indicator of how much electricity you can expect
the unit to use - the higher the SEER, the more efficient the unit, and the less
power it consumes while cooling your house. Of course, the higher SEER units also
generally cost more.

AFUE stands for Annual Fuel Utilization Efficiency, and is a rating applied to gas
furnaces. It is similar to a SEER for air conditioners in that it basically tells
you how much gas the furnace will burn to heat your home. As with SEER, a higher
AFUE rating means less gas consumption (and lower energy bills).

There is no hard and fast rule, but a standard "rule of thumb" for R-22
home systems is about 15 - 20 degrees cooler than room temperature. So if your home
is at 80 degrees, you would expect to have 60 - 65 degree air coming from your vents.
This is a very rough approximation, mind you, and depends on many things
- for example, if your home is extremely hot 90+ degrees) you most likely won't
get that much temperature drop. Also, if your ducts run through your attic, you
most likely will not get as much temperature drop during peak summer temperatures.

This could be caused by a number of things - bad indoor blower motor, defective
thermostat or fan relay - but often it's caused by the system icing up on the
evaporator (indoor) coil. Icing can be caused by many things, but the most common
are dirty filters and low refrigerant charge. You can't fix the second, but
you can change the filter. If your unit is iced up, here's how to thaw it out:

Turn your thermostat's Heat-Off-Cool switch to the Off position

Turn your thermostat's On - Auto switch (the Fan switch) to the On position

Leave your thermostat in this position for about an hour, or until you feel a good
volume of air coming from several vents

Now turn the switches back to their original positions

Of course, you want to fix the problem that caused your freezeup. If the filter
was really dirty, then changing it would probably fix the trouble. However, if the
filter was not overly dirty (a light coating of dust, for example), you'll need
to request a service call
with one of the pros at Wrenn to straighten out your trouble.

The short answer is the temperature at which you're most comfortable. Of course,
the lower you keep your thermostat in the summer, and the higher you keep it in
the winter, the more power/fuel you'll consume so be reasonable with it. Most
utilities suggest 78 degrees in the summer and 68 in the winter. Most people think
that's crazy, of course, and keep the temperature around 75 year round. A good
idea is to check your thermostat with an external thermometer. Buy a decent quality
thermometer (they cost around $3 - $5 dollars at most department stores) and check
the temperature of your home at various places in your home. Compare that with the
setting on your thermostat to see if they match. If not, you may need a new thermostat,
or the one you have may simply need to be calibrated.

Generally 12 - 15 years. Of course, this depends on several factors, among them
how the system has been maintained, quality of construction, and environmental quality.
Regular preventative maintenance has been proven to extend the useable life of your
system, but many people only have their system maintained when it breaks down. Quality
of construction is another factor. Some lower tier units just aren't built as
well as other brands, and they don't tend to hold up well as they age. Units
installed in corrosive atmospheres (i.e. chemical plants, etc) or along the coast
tend to have short life spans as well. Of course, it's not at all uncommon to
come across units which are 25+ years old that are working just fine. The power
consumption is enormous, of course, but mechanically those units are in fine shape.
I hate to say it, but the units being built today don't look to be able to stand
up to 25+ years of work ... if you get 15 years of service out a unit installed
today, I'd consider that about right. As with many other things in the world
today, air conditioners just aren't "built like they used to be".

If you've built a relationship with your HVAC contractor and have used the same
company for several years, the answer is easy - let them do the job. Otherwise,
it's time to do some research. Call friends and neighbors, ask for recommendations.
Get a couple of estimates (normally these are provided free of charge) and narrow
your choices down to 2 - 4 contractors. Call your local Better Business Bureau to
make sure all your finalist are in good standing. Ask each contractor about warranty,
service, etc - in short, get as much information as you can. After arming yourself
with this knowledge, make your decision but remember - the cheapest price is NOT
always the best value, and the most expensive price will not necessarily get you
the best job.

There are a few things which should set off the alarm bells when considering a contractor:

If the salesmen calls you back and tells you "We've only got two of these
left at this price" or "We'll knock xxx dollars off if we can start
by Monday" or some other hard sell tactic, you're probably better off going
with someone else

If the company isn't listed in the local phone book you may be dealing with
an unlicensed contractor. This isn't always the case, however. You could be dealing
with a new contractor, which may or may not be a good thing.

If the company asks for money up front, check them off the list and move to someone
else - no legitimate contractor requires a down payment.

If the company wants to do the job on the weekends or after hours, you may be dealing
with a "weekend warrior" who may be unlicensed, uninsured, and unbonded.
This may not always be the case, of course. During times of peak demand companies
often work long hours and weekends to try and keep pace with the demand.

If the company "doesn't give written estimates", find another contractor.
This guy is just looking to get his foot in the door.

If the company says "we'll do this without a permit so you won't be
hassled by the inspectors", find someone else. Either the company is unlicensed
or they have serious problems with the local inspection department - either way,
not good for you.

If the company refuses to give you a price, and instead concentrates on your monthly
payment, chances are you're paying too much for your system. Don't get me wrong - financing can certainly be a good idea, but be sure
that you know exactly what you're paying for.

If the company constantly runs those "Crazy Eddie" ads in the local newspaper, then
you're probably dealing with a national company who has no real desire in fostering
a reputation in the local community. Find a locally-owned company to do your work.
"Crazy Eddie" ads are those which start with some off-the-wall claim like "We're
overstocked, and selling furnaces for $1" or "The boss is away, so we're selling
'em for cost". These are standard high-pressure sales tactics, much like you're
accustomed to seeing with car lots. Avoid these guys like the plague.

Of course, if you're in our service area, you can always rely on the Pros at Wrenn
to provide you professional installation services.
Contact us today for a free estimate.

Generally speaking, yes you should. If, however, you've recently replaced one
component, you may not need to replace everything. For example, if your furnace
was installed within the last 5 - 7 years you probably will be okay just installing
a new condenser and coil. Beware of companies who insist on replacing everything,
or who claim that you'll void warranties the warranty on your air conditioner
if you don't replace the furnace - that's a load of horse hooey. Your condenser
is ignorant of the type of furnace installed with it, and as long as the furnace
moves sufficient quantities of air, you should be fine.

Of course, you can usually get a much better deal on a full system. And, an air
conditioner should be matched to the correct indoor evaporator coil. Your installing
contractor may tell you this, and he would be telling you the truth in that regard.

By doing a Manual J load calculation on your home. Manual J load calcs are worksheets
put out by the Air Conditioning and Refrigeration Institute (ARI) that assist contractors
in determining exactly what size comfort system should be installed in your home.
There are some "rules of thumb" - in our area, 700 square feet per ton
- but these don't always work, especially for older homes or homes with a lot
of windows and doors. If you're unsure, ask your contractor about doing a Manual
J load calculation. Don't be surprised is there's a charge for doing this,
however - it takes a good bit of time and specialized knowledge to properly perform
a Manual J calculation.

Zoning is when your contractor "divides" your home into different sections, based
on your heating/cooling needs, lifestyle, home layout and other factors. Basically,
it allows you to heat or cool different portions of your home at different temperatures.
For example, if you have a guest room or suite that's in the same living space as
the main house, you might want to zone that section of your home. Many people will
zone a family room/playroom separately from the main house, or the bedroom sections
of the home. While this used to be very expensive, the current crop of residential
zoning systems make this an affordable option.

Well, you can always install zoning, but in some cases it may not be as affordable
as others. In order to correctly zone a home, the ductwork must be designed and
installed so that the separate "zones" can be controlled independentaly on each
other. In some cases - and especially in tri-level homes - this is not possible
without tearing into the home's walls, ceilings, and floors. Also, sizing requirements
for zoned homes may be different, so your current HVAC system may not be adequate
(or may be too large, especially if you've had it changed recently). If you're in
our service area, contact us
for a free Zoning inspection. Our service techs can tell you what it will take to
finally get rid of thos hot/cold spots.

Packaged systems are "all in one" units. They combine a heating unit (aka
furnace) with a cooling system, blower, and all the necessary controls and such
needed to make the system run. Package units are large, normally much larger than
split systems and are directly connected to your home's duct system.

Split systems have separate heating and cooling pieces. The heating section is installed
in or under the house (along with the evaporator coil, which is part of the cooling
system) and the cooling section is installed outdoors. The cooling section is connected
to the evaporator coil with copper pipes - one large and one small. Basically, if
you see two copper pipes running from your outside unit into your house, you have
a split system.

Often the simplest way to determine this is to look at your thermostat. If you see
an Emergency Heat or Supplemental Heat setting, chances are you have a heat pump.
Of course, many times the thermostat has been changed, either by the homeowner or
a weekend warrior, and the wrong type of thermostat has been installed. You can
look at your outside unit; many times the words "Heat Pump" will be on
the label somewhere. If your outside unit runs during the winter, then you have
a heat pump. Otherwise, you can just give us a call and let us know the make and
model of your unit and one of our techs will let you know exactly what you have!

You can, but you may be shooting yourself in the foot. Air conditioners not only
cool the home, they also remove humidity. In sub-tropical climates, like the Southeastern
US, this is as important as providing cooled air to the home. In order for an air
conditioner to remove moisture, the system must be running, and an oversized unit
generally tends to run for a very brief period of time and shut off. The system
never gets the chance to dehumidify, which results in a cool, clammy home - not
comfortable. It's okay to oversize your system a little bit - say 1/2 ton or
so - but to double the size needed is just asking for mold and mildew problems,
along with poor cooling performance.

All new air conditioners should come with a manufacturer's warranty. Most legitimate
contractors also provide you with a one year labor warranty (some more, some less).
Generally speaking, there should be NO charge to repair an air conditioner which
is less than one year old, assuming the damage was not caused by negligence or acts of God. That said, there are some instances which could generate
a charge for service:

If the unit was struck by lightning or some other voltage surge, or was damaged
by some other act of nature, your manufacturer's warranty will NOT cover this.
Normally, however, your homeowner's insurance will cover the cost of this repair,
minus any deductible.

If the damage is the result of negligence (i.e. you didn't change your filter,
or your unit is full of dirt and debris), your warranty won't cover this. Preventative
maintenance is YOUR responsibility

If the problem comes from some other area of your system, your warranty may not
cover this. For example, if your contractor replaced your outside unit ONLY, and
the indoor coil is now leaking refrigerant, your air conditioner's warranty
won't cover that - nor would you expect it to. If, however, you had a full system
replacement, then (barring natural causes or negligence), your system should be
covered for any problem.

Of course, read your warranty papers thoroughly when purchasing a new system, and
keep those papers in a safe place. Your equipment warranty is through your manufacturer,
but your labor warranty is normally provided by your dealer.

There really is no "normal" cycle for an air conditioner - it all depends
on the size of the system, whether it's properly sized for the house, how much
"load" (i.e. heat) is on the house, etc Assuming
an outdoor temperature of 85 degrees and an indoor setpoint of 76, a system that
is properly sized, in proper working order, installed in a home with adequate insulation
overhead and underneath with good windows and doors should run about 20 - 30 minutes
before cycling off. It would typically stay off about 15 - 20 minutes. Of course,
as the outdoor temperature goes up, your unit will have to run longer to compensate
for this. When temperatures top 95 degrees - especially with high humidity conditions
- you can pretty much expect your system to run significantly longer.

Technically speaking, "Freon" is a trademark used by the Dupont corporation
for their line of refrigerant products. It's come to be a standard, however,
much like "Xerox" has to the copy industry. Freon - or, more correctly,
R-22 - is a chemical that is used by air conditioning systems to move heat. There
are many different type and formulas of refrigerant; your home air conditioner likely
uses R-22 (although some newer models are using R-410), while your car probably
uses either R-12 or R-134a. All these are blends of chemicals; R-22 is actually
"chlorodifluoromethane", while R-12 is dichlorodifluoromethane - quite
a mouthful, and it's much easier to say "R-22" or "R-12".

Time to remember basic high school physics - There is no such thing as cold, there
is only absence of heat. Air conditioners work by removing heat from inside your
home, thereby making humans feel more comfortable. Heat is removed by the refrigerant
in your system. Your indoor blower pulls warm air from inside your home through
your return vents, and pushes/pulls that air over your indoor coil (also known as
your evaporator coil). Your evaporator coil is full of refrigerant, and as the warm
air passed through the fins of the coil, that air transfers it's heat to the
cooler refrigerant inside. The refrigerant is then pumped back outside (the compressor
does this) where the heat is dissipated. This is a VERY simplistic explanation,
of course.

While it's pretty easy for your service technician to tell you the size of your
air conditioner, it's not as easy as it may seem. All manufacturer's have a different
method for showing this - it's almost always included in the model number - but
it can be represented in different ways, depending on the manufacturer. Remeber
this: One ton of Air Conditioning = 12,000 BTUs, so a 2 ton system is rated at 24,000
BTUs, a 3 ton at 36,000 BTUs, etc. Now, look at your model number and see if you
can find a number that is relevant to this; for example:

RRNA024JAZ

is a 2 ton system. The "24" in this number (a Rheem model number, by the way) indicates
that we have a system rated at 24,000 BTUs. Remeber, though, that this is different
for all manufacturers; if you're not sure,
send us an email with your Model number and Brand of equipment, and
we'll let you know what size you've got!.

Furnaces, on the other hand, are fairly simple to size. Almost every manufacturer
will list the input/output ratings of their equipment. The Input rating is the amount
of heat that the burners actually produce, while the Output rating is the amount
of heat that the furnace actually delivers to the home. The remainder is the amount
of heat lost (which is primarily lost in the flue system). You can roughly determine
the AFUE of your system by using these two figures - divide Input by Output and
you'll get a pretty good approximation of the AFUE of your system! For example,
if your furnace is rated at 100,000 BTU input and 80,000 BTU output, then your AFUE
is 100,000/80,000, or 80%.

Your system capacity depends on various things - the size of the condenser, the
length of the refrigerant lines, etc. Most systems have the "system charge"
stamped on the outside of the unit, but those are simply rough estimates. Your technician
can give you a much better estimate of exactly how much is needed after an onsite
review of your system and the various components.

Technically speaking, yes you can. However, unless you have an EPA card that says
you're certified to possess chlorine-based refrigerant, then attempting to do
so would be a violation of the law. I doubt Big Brother is going to throw you in
jail for it, but look at it from a cost standpoint: You'd need a set of gauges,
a superheat thermometer, and a jug of refrigerant (total cost: around $500), and
then you'd need the technical expertise and experience to know how much refrigerant
to add (too much is worse than not enough). And, if you add too much refrigerant
to the new Scroll compressors, you can permanently damage the compressor ... all
in all, you're better off have one of the pros at Wrenn correct your refrigerant
charge - contact us today for a service
call.

In the early days of heat pump technology, heat pumps had a poor reputation for
heating - poor, mind you, but well deserved. They produced lukewarm air (if you
were lucky and the sun was shining just right) and generally were little better
than a space heater. Today's modern heat pumps, however, don't have those
problems. Most can produce heat which rivals a gas furnace, and they're extremely
efficient. That said - watch out. Some of the less expensive brands use outdoor
thermostats to automatically bring the electric heat strips on when the temperature
drops below a setpoint (usually around 45 degrees), while better built systems can
handle the load even when the temperature drops. Of course, the most important thing
about heat pumps is to have the system properly installed and serviced. The old
saying "I'd rather have a cheap system put in properly than an expensive
system put in by monkeys" makes a lot of sense.

Heat pumps have backup or supplemental heat. Normally, this is in the form of electrical
heat strips. These heat strip come on at various times - for example, when the unit
goes into defrost, or when the inside temperature drops more than a few degrees
below the thermostat setting. However, these strips can also be used to provide
heating in the event of a compressor or other system failure. You should not use
emergency heating for "normal" heating, however, since it's quite
expensive and normally isn't adequate to heat your entire home.

That's not really smoke (at least we hope not), but more likely it's steam.
Your heat pump is a lot like a frost-free refrigerator - both will "ice up",
but both also have a defrost cycle that will help to thaw the system as needed.
If you happen to be outside when your heat pump goes into a defrost cycle, you may
hear some strange noises (a "whooshing" sound, perhaps, or a loud clattering
noise), followed by a cloud of steam coming from your unit. This is perfectly normal
- the unit is using the heat produced by the system to defrost itself, and when
it's finished it will restart in heat mode and continue to heat your house like
always. Of course, if this happens during a mild day, or when there is no visible
ice on the coils, you may have a problem - time to
request a service call with the pros at Wrenn Heating and Air.

Possibly, but normally this is a sign of a much more serious problem. Often this
means your compressor or fan motor has "grounded" or "shorted"
out, and these are repairs a typical homeowner normally can't perform. It could
be something as simple as a burnt wire, but anytime your 230 volt breakers are tripping
it's time to call in the pros as Wrenn.

Most appliances with a standing pilot will have instructions printed on them somewhere.
However, be warned - follow these instructions exactly, since failure to do so can
result in explosions or fire. If you're not confident that you can safely relight
your pilot, call someone else to do it for your. Our service techs can do this for
you, and perform a routine maintenance check while where there.

Yes, we can perform a carbon monoxide test to see if your has elevated levels of
CO. However, your best defense against CO leaks is proactive maintenance. Have your
furnace inspected annually, including your flue pipe and/or chimney. Be aware of
odd odors around your furnace (CO gives off no odor, but often a blocked flue gives
off a "gassy" smell, since the burners normally don't operate correctly
with a blocked flue). If your flue goes into a common chimney with a fireplace,
make sure to install a cap on the chimney to prevent leaves, birds, and other debris
from lodging in the chimney. And always, always install CO and smoke detectors in
your home - and change the batteries every year!

That depends. If you have a heat pump, and you see water around your outside unit
in the winter time, it is probably coming from the defrost cycle. If you see water
around an indoor unit, however, this is NOT normal and could potentially cause serious
damage to your home. Unless you are confident that you can troubleshoot and repair
the problem, it's time to call the pros at Wrenn Heating to handle this situation.

Often this is expected behavior, especially if your a/c is less than 10 years old.
Modern digital thermostats incorporate a delay system that doesn't allow the
system to come on for 3 - 5 minutes after the call for cooling. Some use a "delay
on break" scenario, where the timer starts when the system turns OFF - thereby
reducing the lag on the next startup. Some condensing system also have delay timers
built into them, which can lengthen the amount of delay. Furnaces have always had
delays when turning on. Electric furnaces use sequencers to "stage in"
the heating elements, and those sequencers also control when the fan turns on and
off. Older gas furnaces used temperature switches to turn the fan on/off; modern
furnaces use circuit boards to do this, but both have a 2 - 5 minute delay between
the time thermostat calls for heat and the time the blower comes on. This is done
to avoid cold drafts. By allowing the furnace to heat up before turning on the blower,
we can lessen the impact of the initial blast of cool air while the system clears
the duct system.

Modern air conditioning systems often use fan delay timers to keep the circulating
fan running after the thermostat is satisfied. The reasoning is pretty simple: The
evaporator coil is still cold, so it makes sense to get all the cooling you can
for the money you're spending in energy. Furnaces have always run for a short
time after the call for heating has ended. This, however, is more of a safety feature
than anything else - the fan cools the furnace so you don't have a superheated
box sitting in your attic or crawlspace. Normally, your fan should run about 90
seconds or less after turning off your thermostat. If the delay is significantly
longer than that, contact Wrenn Heating
for service.

A programmable thermostat allows you to set different temperatures at different
times of the day. Some of them allow you to program each day individually (these
are known as "7 day programmable") while other only allow you to program
the weekdays as a group, then Saturday and Sunday individually (these are known
as "5-1-1" programmable). Programmable thermostats can save you money
if used correctly, and if they fit your lifestyle. If you and other members of your
home are always gone during a particular time (for example, if everybody goes to
work at 8:00 a.m. and doesn't return home until 5:00 p.m.) then you can set
your programmable thermostat to raise or lower the temperature during those times.
If your family has a set schedule, then a programmable thermostat will save you
money on your power bills.

Most modern programmable thermostats have "adaptive logic" circuits, which
is just a fancy way of saying that they will bring the system on early enough to
be at your selected comfort level at the time you select - for example, if you program
the thermostat to bring the house to 75 degrees at 5 p.m., a thermostat with adaptive
logic will sample the house temperature throughout the day and turn the system on
far enough in advance to have the home at 75 degrees at 5 p.m. Thermostats without
adaptive logic would simply turn the system on at 5 p.m., regardless of the home's
temperature.

This could be caused by many things, but is most likely a duct problem. You could
have a duct that has come loose or is broken. If the problem has been ongoing, it
could be a design problem. Unless you're pretty handy with a pair of snips,
it's probably time to call in the pros at Wrenn to take care of this.

In some cases, external forces can cause this - for example, if you cut down a large
tree in your yard you may find one room becomes a little warmer in the summer. Inadequate
home insulation can cause this problem as well, especially with blown in-type insulation.
This tends to pack down over time, ultimately leaving you with poor insulation and
poor cooling.

We offer financing for Trane equipment installation through Wells Fargo. With APRs
as low as 3.9% or 36 months Same-As-Cash financing you can enjoy the comfort of
a Trane system for around $100 a month*.